Document that pool config updates skip acquired browsers

[masnwilliams]

Summary

• Add an FAQ entry clarifying that browserPools.update() only reconfigures idle browsers — a browser that's acquired at update time keeps its original config, and releasing it with reuse: true returns it to the pool still on the old config until it cycles out.
• Add a <Note> to the "Update a pool" section of the pools overview covering the same acquired-browser behavior, next to the existing discard_all_idle explanation.

Why

The idle-browser update behavior (discard_all_idle, flush) is already documented, but the consequence for acquired browsers released with reuse: true wasn't called out anywhere. This is a real gotcha: a pool can hold a mix of old- and new-config browsers after an update until the acquired ones drain. The docs now spell out the two ways to force a clean cutover (reuse: false or letting them time out).

Test plan

• Docs-only change; verify rendering in the Mintlify preview (<Note> component + FAQ formatting).

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Project	Status	Preview	Updated (UTC)
Kernel	🟢 Ready	View Preview	Jul 1, 2026, 6:13 PM

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[masnwilliams]

Closing in favor of #431, which covers the same behavior with a stronger <Warning> callout and better FAQ placement. Suggesting there that we also fold in the two upfront ways to avoid a stale browser (reuse: false on release, or letting it die via timeout_seconds).